Insert



r Allg. 3, 1948. A F, v, FLYNT v 2,446,174

INSERT Filed May 21! 1946 INVENTOR.

Patented Aug. 3, 1948 ENT: f.

INSERT Frank-.Vt` Flynt, Los Angeles, Calif,` ApplicationMayZl, 1946-," SerialNo. 671,364!

, This: invention` rela-iras` to; inserts positioned t trium' one; `surface "of va workpiece and?) designed:

tor enable metal-parts; suoni as fasteningf. or 1ocatingixmeans, tortbe heldcinfthe workpiece :so that;A thel parts: 'are :securelyfretainedi therein i :against:

any` slacking; iback, and. enabling*Y :fastening-ff or locating v Eparts to.l ,loe- :seeuredv ini relatively soft, material; 'suchuaspiiastia` for. aluminum;

Plastic umaterialffandf `aluminum, A*for example;

arextooasoft: to u,hold-satisfaetori1yf ordinary: types V off harderrmetalr asteningwmeansdirectly lposi', y

tionedthereini. 'Various methodswot mounting fastening:4 'means by" usef of-'inserts in :sorter ma` terialf. have been proposed? which' necessitated' Working `from both sides of a\work'oiecerorit-he-y a'pplication ofi considerable forcetappliedi directly 9;(31851115', (Cl. :S51-1).,

axially: off the yinsert Eto -foroea lookingfel-ementtinto the xworkpieee: The force vrequired Ito Hposition the :looking` element iinsuch"V constructions may be harmful in positioning inseritsiin' rela-rl Augieneralsrobject" ofi the vpresentf innen-tion-hisl Lto provide insert means which `may lee-inserted ffrom oneffside off a workpiece in which nomaterlial externallv.vr appliedl` .axialf forseA is required to properly :position: thel insert` in? softer materiali Another fobiectaofltne invention :is toprov-ide f asimplyuconstructediinsert byftftie nseof which fastening means` mayy ben-securely held iin maiterial-:softer` thaithefasteni-ng=means:

Another. object oiftheL inventionist toprovide.V insert meansl-forf-mountingin softer materialiby aixscrewingmovementi of aI retaining member to eiectzal longitudinal movement foil* the insert' into the softermaterialT and?y afflock-ingi-- eifect loi? lthe retainingelement:

Another# obect' is to provide'an insert which may bef-readily produced-ina variety oi formsA zafd-aptedf` iorf luse with materials oidierent hardness;l

.Anotherwobjectr is `toprovide` a` greaterloadI carryingfcapaoityin `a blind-S insert than is' pro-t Illia.Y 5f-is fan: elevationalf view of another tornr` Eig: 'lf'isf` ai verticali-section throughtanotherr: formt lofy insert adapted for use with; relatie/:ely: hard material and 4shown mountedstherein: and:

Referrinanow to the drawings, reierenoefnne meral Ift generallywindicates:ai stndznor.` screw f which 'is provided with `az threadedfsteml `1 ,f witha head;` t2; theheaid being considered oaloec at the inner end of the screw. The threadfffonal, the stern,l may" be aistandardvl one.` Thetheadizis provided. Withr vv'ha't'v mayheaterniedasplines 13.? which, vin the" form,` shown; preferalzihnrapen'orfy converge toward the innemend o'thefscrewa: .'llhefi splines have a sharp edge to facilitate theirtentln` into the.:- wonlrpiece,y 4asi Will n laten he" -describedi;`

The; sereinr la!) isv adaptedtotiaocommonate1 at driving: riingrf` t6 which isfwinternal-1w threaded@ `to'` tr on tire .stemofethescrevw andzxwhich': isaqaroe-` videdi: atyitsfperiphery with a secondf'threadi .l Ther-secondthreadhass adasterrleadiorya `greater orvsteepent'piiich tliarr-` the fthreadtofnf thefstem. of L- thefserevoy for xaufreasoizr` n"liic'lriWilli:hen=lorcmghtimit;` later: .Tnethreadl'lifon the exteriortoithen'ing: l 5 `isifcles.igned to rberselficntting .andiwfor tltisapnri-A pose=isainterruptedsbyfthef l1ongiimd-inat@nani-:elsM 2v2- whichiiorm-i-cutting :edgesftor' the interrupted parts of-rthierthread;` Thief-upper fendi of thelringm |61 is: prortidedi withV a; suitable rneanswforr en ab'ling.` `amt-0015400 engages :it to.:1 exerty al torque on` thefring andiinzthe ``torni shownftliering-isf` prof-J vided with a pair or aligned slots yltilfvwhioh'1in-ay.:`

bei fengaged-- by a suitablyfiormed wrench;

Asfpreviously:described, the splines I3 areata-- pered:stewardA the 'endroit therscrevm; thatv-is; theyy converge;- thereby providing: ashead :on` the :Seaview:v which.V is; of i less; cross sections zat"y ritsr, inner endl tirant atxfany other@ point.` Preferablyrthef diamy eter acrossfzthe top-@offene splineswisi somewhat. greaterfit'hanftheLf-fholeffintofiwhichlthe insert into the splines-With `the Wall` zonthe'-hol'e and *prevent* iti' turning-during its acialmovement intofthe# Reference-islmadeiito Fig. 4; inwhich therein` shown .aworkpiece 22 having al'bore "inCiioa'teyiir by referencer-character A and lacomiterlooreinw` dicatedl'fby the `c'hara;:teriB. In'this -vi-evsrl ametal' plate or' other object' Eto be ffastenecli-u tofthe frei-astivelyzsoitfz'workpiece22 lha-s been indicated'fat 23':

In this view the insert is shown fully positioned in the workpiece 22 and the plate 23. secured thereto by means of a fastening element in the form of a nut 24, a washer 25 being interposed between the nut and the plate if desired.

In the operation of securing the insert means in theA workpiece, the head at the inner end of the screw I is positioned within the bore A and locked therein against rotation by a slight, tap or small amount of for-ce applied to vthe Iend of the screw. The driving ring i6 is then screwed down on the stem of the screw until the external thread thereof engages with the wall of the counterbore B. Further rotation of the driving ring serves to cause it to thread itself into the material of the workpiece, while at the same time, by reason of the difference in the pitchof the threads of the ring, forcing the head of the screw down-4 wardly into the bore A of the workpiece. It is to be understood, of course, that the bore A and counterbore B are previously formed in the workpiece and that the diameters of `these bores are such as to leave sufficient material for the splines on the head of the screw to become embedded therein and the outer thread of the driving ring to. screw into. Obviously the counterbore may be provided with a screw thread to receive the driving ring, but this is unnecessary in most materials.

After the insert means has been mounted in the workpiece, as shown in Fig. 4, the member to be secured to the workpiece maybe fastened thereto by means of a nut 24 heretofore de scribed.

In Figs. 5 and 6 there is shown a form of screw which is designed to be used in material softer than that for which the insert previously described is designed, particularly plastic material. In this form of the invention the screw, indicated generally by 25, is provided witha relatively short serrated head 21, the ridged portions 28 thereof extending longitudinally of the head and tapering toward the inner end of the screw so that in effect a tapered serrated head is provided. `This screw is mounted in the workpiece in the'same manner that the insert previously described is mounted, but by reason of the'large number of ridged portions of limited radial ex-V tent provided, is more adaptable for use in relatively softer materials than that form ofthe invention previously described.

Referring now to Figs. 7 and 8, there is illustrated a form of insert lembodying the invention. which is designed primarily for use with relatively harder materials. This insert comprises what will be termed a screw, generally indicated at 30, which has a stem 3l externally threaded at 32 and provided `with a threaded bore 33 in the upper end thereof. The inner end or lower end of the screw has a head-34 from which extend a limited number of external ridges or splines 35 which taper toward the end of the head. In this form of the invention the head is more elongated than in the forms previously described.

In order to facilitate the entry of the screw 30 into the material of the workpiece, indicated at 31, the lower end of the head is recessedat 38 to provide a cutting edge 39. In this form of the invention the screw 3l) is driven into the bore indicated at A' by the threading of the driving ring 4| into the counterbore B', the driving ring being internally threaded at 42 to screw onto the stem of the screw and being externally threaded at 43 with a self-cutting thread of steeper pitch than the internal thread to thread into the workpiece,

4 and simultaneously drive the screw into the workpiece. As the screw is driven into the workpiece, the cutting edge 3.9 on the inner end of the head facilitates entry of the head and any cuttings or scrapings cut from the wall of the bore will be accommodated in the normal recessed portion 44 at the bottom of the bore A and by the recess 38 in the head of the screw.

With this formI of the invention a fastening elementv may be rscrewe'djinto the threaded hole 33 in the screw for thepurpose of securing an element to the workpiece.

It has been found that the construction described affords a secure retention of the insert in anyfmaterial axial force to be applied to the insert means externally of the workpiece in order to properly position the insert means in the workpiece.

I claim:

1. An insert device for providing mounting for a relatively hard object in a bore of softer mate- `rial, comprising an externally threaded stem having a peripherally splined head on its inner end,

said stem being insertable fromr one side of the workpiece axially head rst into-the bore with the splines engaging the side wall of the bore, a driving ring insertable into said bore around the stem, said ring having an internal thread engageable with the thread on the stem and an external thread of relatively steep pitch engageable. with the side wall of the base and being formed to be engageable by a torque applying tool, and means associated wit-h the outer end of `the stem for re.

ceiving said object.

2. An insert device as set forth in claimy 1` in` which the external thread on said driving ring isV interrupted to provide a self-cutting thread.

5. An insert device for use as described, comprising an inner member having an externally` threaded stem and having a splined head, the splined portion of said head being tapered toward the end of the head, and adriving ring hav-` ing an internal thread adapted to screw onto..

the stern of said inner member and having an external .cutting thread formed-about its periphery of steeper pitch than said internal thread.

6.y An insert device for use as described comprising an innermember having an externally,r threaded stem and having a splined head, the.`

splined portion of said head being tapered toward the endl of the head, a driving ring having an internal thread adapted to screw onto the stem lof said inner member and having an-ex-` ternal cutting thread formed about its periphery of steeper pitch than said internal thread, and.

means on said inner member for securing `a fas.- tening element thereto. l

7. An insert device for use as described com'- prising an inner member having an externally threaded stem and having a splined head, the splined portion of said head being tapered toward the end of the head, and a driving ring having an internal thread adapted to screw onto the stem of said inner member and having 'an ex-A ternal cuttingthrea'd formed about its periphery of steeper pitch than said internal thread, said stem being provided with a recess and with means therein engageable by a fastening member for securing the fastening member to said inner member.

8. An insert device for use as described com prising an inner member having an externally threaded stem and having a sp-lined head, the splined portion of said head being tapered toward the end of the head, said head having a recess therein at the end providing a cutting edge, and a driving ring having an internal thread adapted toscrew onto the stem of said inner member and having an external cutting thread 6 formed about its periphery of steeper pitch than said internal thread. l

9. An insert device for use as described cornprising an inner member having an externally threaded stern and having a serrated head, the serrations thereof extending longitudinally of the head and tapering toward the end of the head, and a driving ring having an internal thread adapted to screw onto the stem of said inner member and having an external cutting thread formed about its periphery of steeper pitch than said internal thread.

FRANK V. FLYNT. 

